> So we arrive back at the Great Filter problem. The dinosaurs lived on> earth for millions of years, but never evolved into tool-using creatures.> Why?> > Terence McKenna has suggested that when our ancestors discovered> psychedelic mushrooms, that stimulated them to start thinking, talking,> and using tools. That was when they broke through the filter and> started making progress. Without mushrooms, we could have been> stuck in an evolutionary cul de sac for eons, like the dinosaurs.> > Lyle

Why should psychedelic substances have been available to our ancestors
but not the dinos?